Even IF a sofa wasn't in the budget, there's always the floor.
Or, do what people have done for centuries, use the bed ALONE by sleeping in shifts.
That reminds me of a story my dad used to tell when I was about 5 years old.
He said he grew up so poor that he and his brother had to "share" one set of clothing.
Dad went to school on ODD numbered days, his brother went on EVEN numbered days.
I asked my mother one day about that story, and she laughed, "Your dad had no brothers, only two sisters".
Of course, after I was married and we had small children, I'd regale them with my stories of sacrifice and suffering, too.